08/04/2015 Idaho DEQ Smoke Forecast

Updated 1000am MDT Tuesday, August 04, 2015

Valid through Noon MDT Wednesday, August 05, 2015

Smoke Outlook

Air quality is forecast to remain in the Moderate to Unhealthy for Sensitive Groups air quality category across the northern Panhandle with short term readings in the Clearwater drainages and across the Idaho Panhandle.  Impacts are from regional fire burning in primarily in Washington State.  The Air Quality Forecast and Caution for Boundary, Bonner, Kootenai, Shoshone, and Benewah counties has been lifted.

Today will be a slightly calmer day-but still active- as one upper level low moves out of our area and another moves in.  Temperatures will be near normal and a slight possibility of afternoon thunderstorms in all airsheds in southern Idaho exists with the highest threat over the Southern Magic Valley and southeast Idaho.  Surface wind speeds will be between 5-15 mph.  The biggest concern today will be gusty conditions near storms with gusts up to 40-50 mph across southern Idaho.  There is a Red Flag Warning for much of southwest Idaho today for high winds and lightning.  Surface wind direction will be from the northwest in the Treasure Valley with west-southwest winds across the remainder of southern Idaho with a late turn from east to southwest in the Magic Valley.  Mixing heights will range from 5,000-9,000 feet AGL.  Transport wind speed will be between 5-20 mph and be generally from the west-southwest except across the Treasure Valley where northwest wind directions will occur.

The upper level low currently off the coast of BC will continue to track towards northern Idaho and will account for locally breezy surface and transport winds.  This system will promote dry conditions through the day today.  Isolated thunderstorms are possible along the Canada/Idaho border late today.  Surface wind speeds will range from 10-20 mph and be from the west-southwest with west-northwest winds across the Camas Prairie and Palouse.  Mixing heights are expected to from 7,500-10,000 feet AGL over all air sheds.  Skies will be mostly to partly sunny this afternoon.  The wind aloft over northern Idaho this afternoon will be from the southwest and will range from 15-25 mph except across central Idaho where winds will be from the west-northwest at 10-15mph. 

The strongest smoke impacts are occurring across the Idaho Panhandle with light impacts through the Hells Canyon and Clearwater drainages.  This will continue into the afternoon as cloud cover and higher moisture levels associated with the upper level low pressure system persist into Wednesday.  Given the current location of the upper level low, expect impacts from fires burning in central Washington to affect most of the Columbia Plateau with a small chance to impact the Palouse and Clearwater airsheds.  Fires along the Idaho/Washington border will continue to affect the northern Panhandle today roughly from I-90 and north.  By Wednesday, this system may allow for decreased fire behavior and atmospheric scouring of particulates. Light impacts should be expected as far south as the Lower Treasure Valley, including a swath running southwest to northeast through McCall and the Central Idaho Mountains into Salmon.

View DEQ near-real time monitoring at:  http://airquality.deq.idaho.gov/

Smoke forecasts are dependent on predicted fire growth and weather.  If conditions change unexpectedly, impacts could occur.  When visibility starts to go below 5 miles, sensitive groups should minimize outdoor activities.  Everyone else should minimize prolonged or physical activity outdoors.  Visit the Idaho Smoke Blog for more information at http://idsmoke.blogspot.com/

Your eyes are your best tools to determine if it’s safe to be outside. Even if you smell smoke, the air quality may still be good.

AQI Category	Visibility (miles)
Good	11+
Moderate	6-10
Unhealthy for Sensitive Groups	3-5
Unhealthy	1½  -2¾
Very Unhealthy	1-1¼
Hazardous	Less than 1

How to estimate air quality based on visibility for areas without an air quality monitor or airport visibility estimate:
a. Face away from the sun.
b. Determine the limit of your visible range by looking for targets at known distances (miles).
c. Visible range is when an object you can easily see in the distance disappears.
d. Use the visibility values above to determine the local wildfire smoke category.